Incestuous adultery means unlawful intercourse between relatives or between persons who are closely related.
In Cook v. State, 11 Ga. 53 (Ga. 1852), the court held that “What constitutes the crime of incestuous adultery, or, its elements, are marriage of defendant, the fact of sexual intercourse, and the relation of the parties within the Levitical degrees.” Further in Mosley v. State, 65 Ga. App. 800 (Ga. Ct. App. 1941), the court observed that “Rape and incestuous adultery are different in the nature of the wrong done and in the facts which constitute them. Neither includes the other, and the defendant may be convicted of either, with or without allegation or proof of some fact essential to the other. Carnal knowledge of the female is a fact common to both. If it is with force and against her will the crime is rape, whether the female be under or over the age of consent and whether she be the defendant's daughter or not. The fact that she is his daughter is immaterial. If she is his daughter and under age of consent, and the force, if any, used by the defendant was mere authority or influence, the crime is incestuous adultery, and the fact that the force used can not be said to be that violence which constitutes rape.”